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Wyszukujesz frazę "benthic sediments" wg kryterium: Wszystkie pola


Wyświetlanie 1-5 z 5
Tytuł:
Characteristics of the macro - and microelements in benthic sediments of selected mid-field ponds
Autorzy:
Brysiewicz, A.
Ligocka, K.
Powiązania:
https://bibliotekanauki.pl/articles/101069.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
benthic sediments
mid-field ponds
macroelements
microelements
chemical composition
Opis:
The agricultural landscape of Western Pomerania is characterised by frequent occurrence of small, post-glacial water ponds commonly called mid-field ponds. They serve numerous important functions, both with regard to agriculture and ecology. Due to their specific location in the agricultural landscape, they are exposed to permanent and strong anthropic pressure, which often translates into pollution of surface water and benthic sediments with macro-and microelements. This study attempts to assess and determine the level of macro – and microelements in benthic sediments, depending on the type of agricultural production, on the example of selected mid-field ponds. The assessed benthic sediments of both ponds were characterised by varied macro - and microelement levels, depending on the collection site and the depth of their deposition. Based on the performed chemical analyses it was found that both observation points in the pond Żelisławiec were characterised by the highest concentrations occurring in the top layer (0-5 cm), which is related to the fact that there are areas of agriculture in the pond basin with the use of mineral and organic fertilisation and occurrence of higher water erosion. And the other assessed mid-field pond (Stare Czarnowo) showed the highest concentration of microelements in the middle layer, 5-15 cm. Statistical analyses revealed that statistically significant differences were observed only for potassium levels, depending on the type of agricultural production in the basin of both assessed ponds. This may result from various types of agricultural crops (Brassica napus L. var. napus and ×Triticosecale Wittm. ex A.Camus) and intense fertilization of arable land in Stare Czarnowo. Statistically significant differences in particular layers of sediment confirm that depending on the type of agricultural activity, mid-field ponds are supplied with various mineral matter at different times, resulting in its accumulation in benthic sediments.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2018, IV/1; 939-950
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seasonal variability of benthic ammonium release in the surface sediments of the Gulf of Gdańsk (Southern Baltic Sea)
Autorzy:
Maksymowska-Brossard, D.
Piekarek-Jankowska, H.
Powiązania:
https://bibliotekanauki.pl/articles/48426.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
ammonium
spatial variation
seasonal variation
Baltic Sea
sediment
Gdansk Gulf
benthic flux
benthic ammonium
Opis:
This paper describes the seasonal and spatial variations of diffusive sediment– water ammonium fluxes in the western part of the Gulf of Gdańsk (southern Baltic). It assesses the potential environmental controls of these fluxes, such as the inflow of organic matter to bottom sediments and its quality, temperature-induced degradation of organic matter, and the redox potential of sediments. Ammonium fluxes, calculated using Fick’s first law, were always in the direction from the sediment into the water column and differed significantly with respect to sediment type. Fluxes were most intensive in sediments with the highest silt-clay fraction located in the deepest parts of the study area. The mean annual diffusive fluxes of ammonium from sediments to near-bottom water were estimated at 5.24 tonnes km−2 year−1 for silty-clays, 1.85 tonnes km−2 year−1 for silty-sands and 1.03 tonnes km−2 year−1 for sandy sediments. There was a high seasonal variation, with the greatest ammonium release in summer and early autumn, when the temperature of near-bottom water was the highest. On the basis of the calculated diffusive ammonium fluxes, we estimated that approximately 2700 tonnes of N–NH+4 are released annually from the surface sediments of the western part of the Gulf of Gdańsk, providing a minimum of 10% of the mineral nitrogen essential for primary production in surface waters. Our results are undoubtedly underestimated, as we disregarded advective ammonium fluxes, which in some areas of the Gulf of Gdańsk could well be comparable to diffusive fluxes.
Źródło:
Oceanologia; 2001, 43, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does the recent pool of benthic foraminiferal tests in fjordic surface sediments reflect interannual environmental changes? The resolution limit of the foraminiferal record
Autorzy:
Łącka, M.
Zajączkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/191692.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
benthic foraminifera
Hornsund
fjord
hydrology
interannual changes
palaeoceanography
Opis:
Benthic foraminifera tests (living + dead) and conductivity, temperature and depth (CTD) records in Hornsund Fjord (SW Spitsbergen) were studied over five non-consecutive summer seasons during 2002–2011. The data indicated significant changes in the abundance of benthic foraminifera, species composition and the variability of hydrological and micro-environmental conditions in this fjord. The increased inflow of Atlantic Water (AW) resulted in higher foraminiferal biodiversity and a greater number of rare species; however, many of these were fragile and were thus poorly preserved in the sediment. Cold years significantly reduced species richness in the fjord centre, while more stable hydrological conditions with a predominance of opportunistic foraminifera were noted at the fjord head. Elphidium excavatum f. clavata and Cassidulina reniforme exhibited sensitivity to salinity changes and food supply. The dynamic foraminiferal response to hydrological changes led to the conclusion that the annual foraminiferal flux, compounded by the poor preservation of fragile individuals, significantly changed the spatial and interannual composition of the foraminiferal tests remaining in the sediment. Furthermore, only mature individuals are representative of yearlong or multi-year fjord conditions, since the juveniles that bloom during their maximum growth periods in spring can die out under poor summer and winter conditions. The findings of this study indicated that the upper 8 cm of the sediment in the intense depositional systems of the Svalbard fjords provide good representation of recently departed benthic foraminifera, because of their mobility in surface sediments and further sediment compaction. Hence, the corresponding 10- to 15-year resolution in palaeoceanographic investigations seems to be the most reliable.
Źródło:
Annales Societatis Geologorum Poloniae; 2016, 86, 1; 59-71
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Benthic diffusive fluxes of organic and inorganic carbon, ammonium and phosphates from deep water sediments of the Baltic Sea
Autorzy:
Lengier, M.
Szymczycha, B.
Brodecka-Goluch, A.
Klostowska, Z.
Kulinski, K.
Powiązania:
https://bibliotekanauki.pl/articles/2078878.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
biogeochemistry
benthic flux
organic carbon
organic matter
remineralization
dissolved organic carbon
dissolved inorganic carbon
ammonium
phosphate
oxygen availability
deep water sediment
Baltic Sea
Opis:
In this study, Baltic Sea sediments, as a source of dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), ammonium (NH4 +), and phosphates (PO4 3−), were investigated based on samples obtained in 2017 and 2018, shortly after a sequence of inflows from the North Sea that occurred between 2014 and 2017. Two different data sets (I and II) were used to assess benthic diffusive fluxes and thus elucidate both the temporal conditions at the time of sampling (data set I) and the diffusion potential of the sediments (data set II). The estimated fluxes were characterized by a high spatial variability within the whole Baltic Sea and ranged between −0.01 and 3.33 mmol m−2 d−1 for DIC, −0.02 and 0.44 mmol m−2 d−1 for DOC, −40.5 and 1370.1 μmol m−2 d−1 for NH4 +, and −5.9 and 60.9 μmol m−2 d−1 for PO4 3−. The estimated benthic diffusive fluxes indicated a high potential for DIC, DOC, NH4 +, and PO4 3− release from Baltic Sea sediments. The high O2 concentrations in the water column of the Gulf of Bothnia together with major Baltic inflows (MBIs) bringing oxygenated seawater to the Baltic Proper and to some extent the Eastern Gotland Basin regulate the amounts of chemicals released from the sediment. Our study showed that a sequence of inflows has greater impact on the diminution of diffusive fluxes than does a single MBI and that the sediments of the Baltic Proper, even under the influence of inflows, are an important source of C, N, and P (159 kt yr−1 for DIC+DOC, 6.3
Źródło:
Oceanologia; 2021, 63, 3; 370-384
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microphytobenthic primary production on exposed coastal sandy sediments of the Southern Baltic Sea using ex situ sediment cores and oxygen optodes
Autorzy:
Kuriyama, K.
Grundling-Pfaff, S.
Diehl, N.
Woelfel, J.
Karsten, U.
Powiązania:
https://bibliotekanauki.pl/articles/2078927.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
microphytobenthos
primary production
sandy sediment
coastal water
benthic diatom
oxygen consumption
oxygen production
respiration
hydrodynamics
Baltic Sea
Opis:
The shallow coastal water zone of the tide-less southern Baltic Sea is dominated by exposed sandy sediments which are typically inhabited by microphytobenthic communities, but their primary production is poorly studied, and hence four stations between 3.0 and 6.2 m depth were investigated. Sediment cores were carefully taken to keep the natural layering and exposed in a controlled self-constructed incubator. Respiratory oxygen consumption and photosynthetic oxygen production were recorded applying planar oxygen optode sensors. We hypothesized that with increasing water depths the effects of wind- and wave-induced erosion and mixing of the upper sediment layer are dampened and expected higher microphytobenthic biomass and primary production in the incubated cores. Our data partly confirm this hypothesis, as cores sampled at the most exposed stations contained only 50% chlorophyll a m−2 compared to the deeper stations. However, primary production was highly variable, probably due to fluctuating sediment-disturbing conditions before the cores were taken. Due to these physical forces sand grains were highly mobile and rounded, and small epipsamic benthic diatoms dominated, which preferentially occurred in some cracks and crevices as visualized by scanning electron microscopy. The data fill an important gap in reliable production data for sandy sediments of the southern Baltic Sea, and point to the ecological importance and relevant contribution of microphytobenthic communities to the total primary production of this marine ecosystem. Oxygen planar optode sensor spots proved to be a reliable, sensitive and fast detection system for ex situ oxygen exchange measurements in the overlying water of intact sediment cores.
Źródło:
Oceanologia; 2021, 63, 2; 247-260
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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